One of the steps for manufacturing a semiconductor is a step in which a predetermined film-forming treatment is carried out on the surface of a substrate (a treated substrate in which a fine electrical circuit pattern is formed using a silicon wafer, glass, or the like as a base). Among such predetermined film-forming treatments, methods are being actively researched in which the electrical film of a gate insulation film is made thinner and a silicon (Si) oxide film/oxynitride film is converted to a High-k (high dielectric constant) film in a step in which a gate insulation film is formed. Sputtering and CVD (Chemical Vapor Deposition) are being studied as methods for forming ZrO2, HfO2, and other High-k films. CVD is widely used for mass production due to the advantages in step coatability and other properties, as well as the ease with which the raw materials for forming the film can be exchanged.
MOCVD (Metal Organic Chemical Vapor Deposition), which is one type of CVD, is used to form High-k films. In MOCVD, an organometallic raw material is used as the raw material gas. There are various organometallic raw materials, and each of these materials has been researched. Examples of HfO2 and HfSiO4 raw materials that are used include Hf[OC(CH3)3]4(Hf-OtBu), Hf[OC(CH3)2CH2OCH3]4 (“Hf-MMP” hereunder), Si[OC(CH3)2CH2OCH3]4 (“Si-MMP” hereunder), Hf[O—Si—(CHs)]4(Hf—OSi), and Si(OC2H3)4(TEOS). Among these, Hf-MMP and Si-MMP are liquid at about 30° C. and normal pressure. Therefore, such liquid raw materials are heated and, depending on the vapor pressure, are converted to a gas before being used. There are CVD methods that use Hf-MMP, which is one of the MOCVD raw materials (e.g., see Patent Document 1).
[Patent Document 1]
JP-A 2004-6699